Percutaneous gastrostomy is currently the standard route for prolonged enteral feeding. Due to the simplicity and speed of technology and the development of the equipment, gastroenterologists or radiologists are increasingly sought, and the placement is accessible to any endoscopist or radiologist.
There are two placement techniques:                the endoscopic <<pull>> technique, mainly used by gastroenterologists: the steril PEG kits generally include a puncture trocar, a double strand of wire, a tubular gastrostomy catheter, a flange-type internal means of retention, an external fixation flange: are used, to grasp the intragastric wire, a diathermic cove or biopsy forceps;        the <<push>> technique via the abdominal wall, used mainly by radiologists: in this case anchors enable binding of the stomach to the abdominal wall for the time required for the formation of adhesions between the external part of the stomach and the abdominal wall. A catheter balloon is then positioned through the abdominal wall using a dilator and a peel-off nozzle.        
The catheters are generally made of silicone or polyurethane, inert and well tolerated materials. Various sizes or Charrières are available, the small catheters being blocked more easily.
There are extractable and non-extractable catheters.
Non-extractable catheters, to be replaced, should be cut flush with the cutaneous orifice. The internal device is then pushed into the stomach.
The internal means of retention can be retrieved by endoscopy, an operation that can turn out to be delicate, or evacuated via the natural routes with risks of obstruction and intestinal perforation.
The advantage of non-extractable catheters lies in their relatively rigid internal flange thus resisting an attempt of pulling out by an agitated restless patient.
The extractable catheters have a retractable removable internal flange, or a deflatable retention system, enabling their removal via the cutaneous orifice by firm tension.
The advantage of these flexible systems is to be able to pass through a severe stenosis, avoiding endoscopy, but they have less resistance to pulling out.
The choice between extractable and non-extractable catheters, made of silicone or polyurethane, depends on the indication, taking into account the advantages and disadvantages of each type of catheters.
The extractable catheters made of silicone are suitable for temporary enteral feeding.
Non-extractable or polyurethane catheters are more suitable for permanent enteral feeding or a restless patient.
The replacement of the gastrostomy catheters may be needed in case of obstruction, tube deterioration (cracking, porosity, expansion, colonization by candida).
The majority of replacement devices are catheters with a water-inflatable balloon, made of silicone. Their suitability for the gastric environment and an external retention flange enables safe use.
There is also a shorter gastrostomy button and on bare skin which, because of its aesthetic advantage and comfort, is indicated in the young or outpatient subject. It cannot be installed initially except with difficulty, however, and comes most often as replacement for a catheter already positioned in the stomach.
The catheter according to the invention is the type including:
a) a tubing designed to pass through the stomach and abdominal walls of the subject;
b) an internal means of retention, joined to the aforementioned tubing, designed to be maintained pressed against the inner face of the stomach wall and to disengage itself from the aforementioned tubing by biodegradation;
c) an external flange, traversed by the aforementioned tubing, designed to be pressed against the external face of the abdominal wall and exert, in cooperation with the internal means of retention, a pressure adapted to press the stomach wall against the abdominal wall in the area of the stoma.
The closest prior art document has the reference WO99/17708.
The internal means of retention that is described therein is constituted:                by a balloon, non-detachable from the tubing, causing, during its passage through the stoma, traumas;        by a biodegradable collar positioned between the aforementioned balloon and the stomach wall and detachable from the tubing only after total biodegradation.        